<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
  <style>
    #d1{
      width:200px;height:200px;
      border:10px dashed red;
        /*设置圆角;值越大越圆,超过边缘一半时为正圆*/
        border-radius:30px;
    }
    #d2{
        width:200px;height:200px;
        border:10px dashed blue;
        /*默认情况下给元素添加内边距会影响元素的宽高*/
        padding-top:100px;
        padding-left:100px;
        /*添加此样式后内边距将不在影响元素的宽高*/
        box-sizing: border-box;
    }








  </style>
</head>
<body>
<div id="d1">边框测试</div>
<div id="d2">内边距测试</div>
</body>
</html>